Stamped metal female tab receiving electrical receptacles have become widely accepted and utilized, particularly in the automobile industry, where a positive latching characteristic is required for reliability of operation. A typical prior art female receptacle is stamped and formed from sheet metal and comprises a generally channel shaped receptacle portion having a base and upstanding side walls with the free edge of the sidewalls being bent towards each other to overlie the base to form the channel shaped receptacle. Some of the prior art designs include a lock and/or a tongue which is struck out from the base to extend rearwardly within the receptacle portion from a front root end to aid in the retention of the male tab. In still other prior art designs, the tongue is not struck out from the base but extends initially from a forward edge of the base and is then bent back to extend rearwardly within the receptacle.
While the prior art female receptacles have performed satisfactorily, reliability problems have been experienced with this kind of terminal which relies predominantly on the flexural characteristics of the tongue, if present, along with the flexural characteristics of the upstanding sidewalls to obtain the retention loads. With continued insertion and withdrawal of the tab, the holding integrity of the female receptacle degrades due to the plastic deformation of either the tongue or the sidewalls. Particularly, the sidewalls will have a tendency to open up and increase the size of the receptacle which then leads to lower retention loads. In addition, the plastic deformation can lead to loosening of the tab within the receptacle which may cause intermittent electrical connection between the two pieces, especially when the connection is subjected to vibration.
Accordingly, what is needed is a stamped metal female receptacle which will retain its retention characteristics after multiple insertion and withdrawals of the male tab.